[PATCHv4 25/29] drm/omap: displays: panel-dpi: Support for handling backlight devices

@@ -9,6 +9,7 @@ Optional properties:
 - enable-gpios: panel enable gpio
 - reset-gpios: GPIO to control the RESET pin
 - vcc-supply: phandle of regulator that will be used to enable power to the display
+- backlight: phandle of the backlight device
 
 Required nodes:
 - "panel-timing" containing video timings

@@ -22,6 +23,8 @@ lcd0: display@0 {
         compatible = "samsung,lte430wq-f0c", "panel-dpi";
         label = "lcd";
 
+        backlight = <&backlight>;
+
         port {
             lcd_in: endpoint {
                     remote-endpoint = <&dpi_out>;

@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/regulator/consumer.h>
+#include <linux/backlight.h>
 
 #include <video/omap-panel-data.h>
 #include <video/of_display_timing.h>

@@ -30,6 +31,8 @@ struct panel_drv_data {
 
 	struct videomode vm;
 
+	struct backlight_device *backlight;
+
 	/* used for non-DT boot, to be removed */
 	int backlight_gpio;
 

@@ -97,6 +100,11 @@ static int panel_dpi_enable(struct omap_dss_device *dssdev)
 	if (gpio_is_valid(ddata->backlight_gpio))
 		gpio_set_value_cansleep(ddata->backlight_gpio, 1);
 
+	if (ddata->backlight) {
+		ddata->backlight->props.power = FB_BLANK_UNBLANK;
+		backlight_update_status(ddata->backlight);
+	}
+
 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 
 	return 0;

@@ -113,6 +121,11 @@ static void panel_dpi_disable(struct omap_dss_device *dssdev)
 	if (gpio_is_valid(ddata->backlight_gpio))
 		gpio_set_value_cansleep(ddata->backlight_gpio, 0);
 
+	if (ddata->backlight) {
+		ddata->backlight->props.power = FB_BLANK_POWERDOWN;
+		backlight_update_status(ddata->backlight);
+	}
+
 	gpiod_set_value_cansleep(ddata->enable_gpio, 0);
 	regulator_disable(ddata->vcc_supply);
 

@@ -209,6 +222,7 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
 {
 	struct panel_drv_data *ddata = platform_get_drvdata(pdev);
 	struct device_node *node = pdev->dev.of_node;
+	struct device_node *bl_node;
 	struct omap_dss_device *in;
 	int r;
 	struct display_timing timing;

@@ -236,10 +250,19 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
 
 	ddata->backlight_gpio = -ENOENT;
 
+	bl_node = of_parse_phandle(node, "backlight", 0);
+	if (bl_node) {
+		ddata->backlight = of_find_backlight_by_node(bl_node);
+		of_node_put(bl_node);
+
+		if (!ddata->backlight)
+			return -EPROBE_DEFER;
+	}
+
 	r = of_get_display_timing(node, "panel-timing", &timing);
 	if (r) {
 		dev_err(&pdev->dev, "failed to get video timing\n");
-		return r;
+		goto error_free_backlight;
 	}
 
 	videomode_from_timing(&timing, &ddata->vm);

@@ -247,12 +270,19 @@ static int panel_dpi_probe_of(struct platform_device *pdev)
 	in = omapdss_of_find_source_for_first_ep(node);
 	if (IS_ERR(in)) {
 		dev_err(&pdev->dev, "failed to find video source\n");
-		return PTR_ERR(in);
+		r = PTR_ERR(in);
+		goto error_free_backlight;
 	}
 
 	ddata->in = in;
 
 	return 0;
+
+error_free_backlight:
+	if (ddata->backlight)
+		put_device(&ddata->backlight->dev);
+
+	return r;
 }
 
 static int panel_dpi_probe(struct platform_device *pdev)

@@ -321,6 +351,9 @@ static int __exit panel_dpi_remove(struct platform_device *pdev)
 
 	omap_dss_put_device(in);
 
+	if (ddata->backlight)
+		put_device(&ddata->backlight->dev);
+
 	return 0;
 }